The Ultimate Comparison – IMAP vs POP3 vs SMTP

SMTP, POP3, and IMAP are specialized TCP/IP protocols used for sending and receiving emails. As developers, it is essential to understand these protocols to meet the modern application requirements.

What is SMTP Protocol ?

The full form of SMTP is a simple mail transfer protocol. It is an application layer protocol. SMTP is a TCP/ protocol used for sending and receiving mail. It is generally used in email clients like Gmail, Yahoo, and Apple Mail. It is a push protocol that is used to push the mail over the user’s mail server. It is text based protocol. This means that the communication between the client (sender’s email program) and the server (sender’s outgoing mail server or recipient’s incoming mail server) is carried out using plain text commands and responses.

What is the POP Protocol ?

The full form of POP is post office protocol. It is used to pull the mail from the receiver’s mail server. It works on TCP port number 110. It is a simple protocol to download the email. we can read email after download only.

What is the IMAP Protocol ?

IMAP stands for Internet message access protocol. It is like POP protocol. It is an advanced version of the POP protocol. It is also used to pull the mail from the receiver’s mail server. It works on the TCP port number 143.

Comparison Between SMTP vs POP vs IMAP

SMTP	POP	IMAP
Stands for Simple mail transfer protocol	Stands for Post Office Protocol.	Stands for Internet Message Access Protocol.
Used for sending mail.	Used for retrieving mail.	Used for retrieving mail.
It is push protocol.	It is pull protocol.	It is pull protocol.
It work between sender’s mail server to receiver’s mail server and sender and sender’s mail server.	It work between receiver and receiver’s mail server.	It works between receiver and receiver’s mail server.
It does not store mail on server it just send the mail.	It download all the mail when it connected to internet.	It store all mail on server and download when it get request to download.
Works on TCP port number 25.	Works on TCP port number 110.	Works on TCP port number 143.
Connection oriented protocol.	Connection oriented protocol.	Connection oriented protocol.
It has persistence TCP connection.	It has persistence TCP connection.	It has persistence TCP connection.
Stateless protocol.	Stateful protocol.	Stateful protocol.
It is in band protocol.	It is in band protocol.	It is in band protocol.
Not used at receiver side.	Used at receiver side.	Used at receiver side.

Terminologies Used in Comparison

Persistence connection

It will establish connection once and used it for multiple object. it does not make connection for each and every object.

State-Full and State-Less

if session information is store between client and server then it is called state-full connection.
if session information is not store between client and server then it is called state-less connection.

In-band connection

Information flow in only single direction between client and server. In other word we can say that it has only single line to transmit data.

Some more Important Comparisons Between IMAP and POP

POP	IMAP
In this mail can be access through one single device at a time.	In this mail can be access from multiple devices.
We can read mail after download only.	We can read mail partially before completing download.
It does not allow the user to organise mail over server.	It allow user to organize the mail over the server.

Frequently Asked Questions

What is the main difference between POP and IMAP ?

Main difference between POP and IMAP is how it handle the mail. POP download and remove the mail from server while IMAP keeps it on server.

What is the use of SMTP ?

It is used for sending emails. It is responsible for transferring outgoing email from sender’s email client to receiver’s mail server.

Can I use SMTP without using IMAP or POP ?

Yes, because SMTP is used for sending email i.e for push. it is not depend on POP or IMAP.